Methods for producing high-density carbon films for hardmasks and other patterning applications

ABSTRACT

Embodiments of the present disclosure generally relate to the fabrication of integrated circuits. More particularly, the embodiments described herein provide methods for producing reduced-stress diamond-like carbon films for patterning applications. In one or more embodiments, a method includes flowing a deposition gas containing a hydrocarbon compound into a processing volume of a process chamber having a substrate positioned on an electrostatic chuck and generating a plasma above the substrate in the processing volume by applying a first RF bias to the electrostatic chuck to deposit a stressed diamond-like carbon film on the substrate. The stressed diamond-like carbon film has a compressive stress of −500 MPa or greater. The method further includes heating the stressed diamond-like carbon film to produce a reduced-stress diamond-like carbon film during a thermal annealing process. The reduced-stress diamond-like carbon film has a compressive stress of less than −500 MPa.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.16/915,110, filed Jun. 29, 2020, which is herein incorporated byreference.

BACKGROUND Field

Embodiments of the present disclosure generally relate to thefabrication of integrated circuits. More particularly, the embodimentsdescribed and discussed herein provide techniques for the deposition ofhigh-density films for patterning applications.

Description of the Related Art

Integrated circuits have evolved into complex devices that can includemillions of transistors, capacitors and resistors on a single chip. Theevolution of chip designs continually requires faster circuitry andgreater circuit density. The demands for faster circuits with greatercircuit densities impose corresponding demands on the materials used tofabricate such integrated circuits. In particular, as the dimensions ofintegrated circuit components reduce to the sub-micron scale, it is nownecessary to use low resistivity conductive materials as well as lowdielectric constant insulating materials to obtain suitable electricalperformance from such components.

The demands for greater integrated circuit densities also impose demandson the process sequences used in the manufacture of integrated circuitcomponents. For example, in process sequences that use conventionalphotolithographic techniques, a layer of energy sensitive resist isformed over a stack of material layers disposed on a substrate. Theenergy sensitive resist layer is exposed to an image of a pattern toform a photoresist mask. Thereafter, the mask pattern is transferred toone or more of the material layers of the stack using an etch process.The chemical etchant used in the etch process is selected to have agreater etch selectivity for the material layers of the stack than forthe mask of energy sensitive resist. That is, the chemical etchantetches the one or more layers of the material stack at a rate muchfaster than the energy sensitive resist. The etch selectivity to the oneor more material layers of the stack over the resist prevents the energysensitive resist from being consumed prior to completion of the patterntransfer.

As the pattern dimensions are reduced, the thickness of the energysensitive resist is correspondingly reduced in order to control patternresolution. Such thin resist layers can be insufficient to maskunderlying material layers during the pattern transfer step due toattack by the chemical etchant. An intermediate layer (e.g., siliconoxynitride, silicon carbine or carbon film), called a hardmask, is oftenused between the energy sensitive resist layer and the underlyingmaterial layers to facilitate pattern transfer because of greaterresistance to the chemical etchant. Hardmask materials having both highetch selectivity and high deposition rates are desirable. As criticaldimensions (CD) decrease, current hardmask materials lack the desiredetch selectivity relative to underlying materials (e.g., oxides andnitrides) and are often difficult to deposit.

Therefore, there is a need in the art for an improved hardmask layersand methods for depositing improved hardmask layers.

SUMMARY

Embodiments of the present disclosure generally relate to thefabrication of integrated circuits. More particularly, the embodimentsdescribed and discussed herein provide techniques for the deposition ofhigh-density films, such as reduced-stress diamond-like carbon films,for patterning applications. In one or more embodiments, a method ofprocessing a substrate includes flowing a deposition gas containing ahydrocarbon compound into a processing volume of a process chamberhaving a substrate positioned on an electrostatic chuck, wherein theprocessing volume is maintained at a pressure of about 0.5 mTorr toabout 10 Torr. The method also includes generating a plasma above thesubstrate in the processing volume by applying a first RF bias to theelectrostatic chuck to deposit a stressed diamond-like carbon film onthe substrate, where the stressed diamond-like carbon film has acompressive stress of −500 MPa or greater. The method further includesheating the stressed diamond-like carbon film to a temperature of about200° C. to about 600° C. for about 15 seconds to about 60 minutes toproduce a reduced-stress diamond-like carbon film during a thermalannealing process. The reduced-stress diamond-like carbon film has acompressive stress of less than −500 MPa and a density of greater than1.5 g/cc. In some examples, the nitrogen-doped diamond-like carbon filmhas a density of greater than 1.5 g/cc to about 2.1 g/cc and acompressive stress of about −20 MPa to about −400 MPa.

In some embodiments, a method of processing a substrate includes flowinga deposition gas containing a hydrocarbon compound into a processingvolume of a plasma process chamber having a substrate positioned on anelectrostatic chuck, where the processing volume is maintained at apressure of about 0.5 mTorr to about 10 Torr. The method also includesgenerating a plasma above the substrate in the processing volume byapplying a first RF bias to the electrostatic chuck to deposit astressed diamond-like carbon film on the substrate. The stresseddiamond-like carbon film contains about 50 atomic percent to about 90atomic percent of sp³ hybridized carbon atoms and has a compressivestress of −500 MPa or greater and a density of greater than 1.5 g/cc.The method also includes transferring the substrate containing thestressed diamond-like carbon film from the plasma process chamber to athermal annealing chamber, and heating the stressed diamond-like carbonfilm to a temperature of about 200° C. to about 600° C. for about 15seconds to about 60 minutes to produce a reduced-stress diamond-likecarbon film during a thermal annealing process. The reduced-stressdiamond-like carbon film contains about 50 atomic percent to about 90atomic percent of sp³ hybridized carbon atoms and has a compressivestress of about −20 MPa to less than −500 MPa and a density of greaterthan 1.5 g/cc to about 2.1 g/cc.

In other embodiments, a method of processing a substrate includesflowing a deposition gas containing a hydrocarbon compound into aprocessing volume of a process chamber having a substrate positioned onan electrostatic chuck, and generating a plasma above the substrate inthe processing volume by applying a first RF bias to the electrostaticchuck to deposit a stressed diamond-like carbon film on the substrate.The stressed diamond-like carbon film has a compressive stress of −500MPa or greater. The method also includes heating the stresseddiamond-like carbon film to a temperature of about 200° C. to about 600°C. for about 15 seconds to about 60 minutes to produce a reduced-stressdiamond-like carbon film during a thermal annealing process. Thereduced-stress diamond-like carbon film has a compressive stress of lessthan −500 MPa and a density of greater than 1.5 g/cc. Also, thecompressive stress of reduced-stress diamond-like carbon film is about40% to about 90% less than the compressive stress of the stresseddiamond-like carbon film. The method further includes forming apatterned photoresist layer over the reduced-stress diamond-like carbonfilm, etching the reduced-stress diamond-like carbon film in a patterncorresponding with the patterned photoresist layer, and etching thepattern into the substrate.

In one or more embodiments, a reduced-stress diamond-like carbon filmfor use as an underlayer for an extreme ultraviolet (“EUV”) lithographyprocess is provided and contains about 50 atomic percent to about 90atomic percent or about 60 atomic percent to about 70 atomic percent ofsp³ hybridized carbon atoms. The reduced-stress diamond-like carbon filmhas a density of greater than 1.5 g/cc to about 2.1 g/cc, about 1.55g/cc to less than 2 g/cc, or about 1.6 g/cc to about 1.8 g/cc, anelastic modulus of greater than 60 GPa to about 150 GPa or about 65 GPato about 80 GPa, and a compressive stress of about −20 MPa to less than−600 MPa, about −200 MPa to about −500 MPa, or about −250 MPa to about−400 MPa.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the disclosurecan be understood in detail, a more particular description of thedisclosure, briefly summarized above, may be had by reference toimplementations, some of which are illustrated in the appended drawings.It is to be noted, however, that the appended drawings illustrate onlytypical implementations of this disclosure and are therefore not to beconsidered limiting of scope, for the disclosure may admit to otherequally effective implementations.

FIG. 1A depicts a schematic cross-sectional view of a deposition systemthat can be used to practice processes according to one or moreembodiments described and discussed herein.

FIG. 1B depicts a schematic cross-sectional view of another depositionsystem that can be used to practice processes according to one or moreembodiments described and discussed herein.

FIG. 2 depicts a schematic cross-sectional view of an electrostaticchuck that may be used in the apparatus of FIGS. 1A-1B, according to oneor more embodiments described and discussed herein.

FIG. 3 depicts a flow diagram of a method for forming a reduced-stressdiamond-like carbon film on a film stack disposed on a substrateaccording to one or more embodiments described and discussed herein.

FIGS. 4A-4B depict a sequence for forming a reduced-stress diamond-likecarbon film on a film stack formed on a substrate according to one ormore embodiments described and discussed herein.

FIG. 5 depicts a flow diagram of a method of using a reduced-stressdiamond-like carbon film according to one or more embodiments describedand discussed herein.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

DETAILED DESCRIPTION

Embodiments provided herein relate to reduced-stress diamond-like carbonfilms and methods for depositing or otherwise forming the reduced-stressdiamond-like carbon films on a substrate. Certain details are set forthin the following description and in FIGS. 1A-5 to provide a thoroughunderstanding of various embodiments of the disclosure. Other detailsdescribing well-known structures and systems often associated withplasma processing and diamond-like carbon film deposition are not setforth in the following disclosure to avoid unnecessarily obscuring thedescription of the various embodiments.

Many of the details, dimensions, angles and other features shown in theFigures are merely illustrative of particular embodiments. Accordingly,other embodiments can have other details, components, dimensions, anglesand features without departing from the spirit or scope of the presentdisclosure. In addition, further embodiments of the disclosure can bepracticed without several of the details described below.

Embodiments described herein, include improved methods of fabricatingreduced-stress diamond-like carbon films with high-density (e.g., >1.5g/cc), high elastic modulus (e.g., >60 GPa), and low compressive stress(e.g., <−500 MPa). The reduced-stress diamond-like carbon filmsfabricated according to the embodiments described herein are amorphousin nature and have a greater etch selectivity along with lower stressthan current patterning films. The reduced-stress diamond-like carbonfilms fabricated according to the embodiments described herein not onlyhave a low compressive stress but also have a high sp³ carbon content.In general, the deposition and annealing processes described herein isalso fully compatible with current integration schemes for hardmaskapplications.

In one or more embodiments, the fabrication or otherwise production ofthe reduced-stress diamond-like carbon film includes depositing ofotherwise forming a stressed diamond-like carbon film on the substrateduring a deposition process, such as a chemical vapor deposition (CVD)process, and then converting the stressed diamond-like carbon film to areduced-stress diamond-like carbon film by annealing the substrates,such as during a thermal annealing process. For example, the method caninclude flowing a deposition gas containing a hydrocarbon compound intoa processing volume of a process chamber having a substrate positionedon an electrostatic chuck and generating a plasma above the substrate inthe processing volume by applying a first RF bias to the electrostaticchuck to deposit the stressed diamond-like carbon film on the substrate.The stressed diamond-like carbon film generally has a compressive stressof −500 MPa or greater, such as from about −600 MPa to about −1,000 MPa.The method also includes heating the stressed diamond-like carbon filmto a temperature of about 200° C. to about 600° C. for about 15 secondsto about 60 minutes to produce the reduced-stress diamond-like carbonfilm during a thermal annealing process.

In some embodiments, the stressed diamond-like carbon films describedherein may be deposited or otherwise formed by CVD, such asplasma-enhanced CVD (PE-CVD) and/or thermal CVD processes, using adeposition gas containing one or more hydrocarbon compounds. In one ormore examples, a deposition gas containing one or more hydrocarboncompounds and optionally one or more dilution gases can be flowed orotherwise introduced into a processing volume of a process chamber. Asubstrate is positioned or otherwise disposed on an electrostatic chuckwithin the processing volume, where the electrostatic chuck has achucking electrode and an RF electrode separate from the chuckingelectrode. The method further includes generating a plasma at and/orabove the substrate by applying a first RF bias to the RF electrode anda second RF bias to the chucking electrode to deposit a stresseddiamond-like carbon film on the substrate.

Exemplary hydrocarbon compounds can be or include ethyne or acetylene(C₂H₂), propene (C₃H₆), methane (CH₄), butene (C₄H₈),1,3-dimethyladamantane, bicyclo[2.2.1]hepta-2,5-diene(2,5-norbornadiene), adamantine (C₁₀H₁₆), norbornene (C₇H₁₀),derivatives thereof, isomers thereof, or any combination thereof. Thedeposition gas may further include one, two, or more dilution gases,carrier gases, and/or purge gases, such as, for example, helium, argon,xenon, neon, nitrogen (N₂), hydrogen (H₂), or any combination thereof.In some examples, the deposition gas may further include etchant gasessuch as chlorine (Cl₂), carbon tetrafluoride (CF₄), and/or nitrogentrifluoride (NF₃) to improve film quality.

The substrate and/or the processing volume can be heated and maintainedat independent temperatures during the deposition process. The substrateand/or the processing volume can be heated to a temperature of about−50° C., about −40° C., about −25° C., about −10° C., about −5° C.,about 0° C., about 5° C., or about 10° C. to about 15° C., about 20° C.,about 23° C., about 30° C., about 50° C., about 100° C., about 150° C.,about 200° C., about 300° C., about 400° C., about 500° C., or about600° C. For example, the substrate and/or the processing volume can beheated to a temperature of about −50° C. to about 600° C., about −50° C.to about 450° C., about −50° C. to about 350° C., about −50° C. to about200° C., about −50° C. to about 100° C., about −50° C. to about 50° C.,about −50° C. to about 0° C., about −40° C. to about 200° C., about −40°C. to about 100° C., about −40° C. to about 80° C., about −40° C. toabout 50° C., about −40° C. to about 25° C., about −40° C. to about 10°C., about −40° C. to about 0° C., about 0° C. to about 600° C., about 0°C. to about 450° C., about 0° C. to about 350° C., about 0° C. to about200° C., about 0° C. to about 120° C., about 0° C. to about 100° C.,about 0° C. to about 80° C., about 0° C. to about 50° C., about 0° C. toabout 25° C., about 10° C. to about 600° C., about 10° C. to about 450°C., about 10° C. to about 350° C., about 10° C. to about 200° C., about10° C. to about 100° C., or about 10° C. to about 50° C.

The processing volume of the processing chamber is maintained atsub-atmospheric pressures during the deposition process. The processingvolume of the processing chamber is maintained at a pressure of about0.1 mTorr, about 0.5 mTorr, about 1 mTorr, about 5 mTorr, about 10mTorr, about 50 mTorr, or about 80 mTorr to about 100 mTorr, about 250mTorr, about 500 mTorr, about 1 Torr, about 5 Torr, about 10 Torr, about20 Torr, about 50 Torr, or about 100 Torr. For example, the processingvolume of the processing chamber is maintained at a pressure of about0.1 mTorr to about 10 Torr, about 0.1 mTorr to about 5 Torr, about 0.1mTorr to about 1 Torr, about 0.1 mTorr to about 500 mTorr, about 0.1mTorr to about 100 mTorr, about 0.1 mTorr to about 10 mTorr, about 1mTorr to about 10 Torr, about 1 mTorr to about 5 Torr, about 1 mTorr toabout 1 Torr, about 1 mTorr to about 500 mTorr, about 1 mTorr to about100 mTorr, about 1 mTorr to about 10 mTorr, about 5 mTorr to about 10Torr, about 5 mTorr to about 5 Torr, about 5 mTorr to about 1 Torr,about 5 mTorr to about 500 mTorr, about 5 mTorr to about 100 mTorr, orabout 5 mTorr to about 10 mTorr. In one or more examples, the processingvolume is maintained at a pressure of about 0.5 mTorr to about 10 Torr,about 1 mTorr to about 500 mTorr, or about 5 mTorr to about 100 mTorrwhen generating the plasma and depositing the stressed diamond-likecarbon film on a substrate maintained at a temperature of about 0° C. toabout 50° C.

The plasma (e.g., capacitive-coupled plasma) may be formed from eithertop and bottom electrodes or side electrodes. The electrodes may beformed from a single powered electrode, dual powered electrodes, or moreelectrodes with multiple frequencies such as, but not limited to, about350 KHz, about 2 MHz, about 13.56 MHz, about 27 MHz, about 40 MHz, about60 MHz, and about 100 MHz, being used alternatively or simultaneously ina CVD system with any or all of the reactant gases listed herein todeposit a thin stressed film of diamond-like carbon.

In one or more embodiments, the stressed diamond-like carbon film isdeposited in a process chamber with the substrate pedestal maintained atabout 10° C. and a pressure at about 2 mTorr, with plasma generated ator above the substrate level by applying a bias of about 2,500 watts(about 13.56 MHz) to the electrostatic chuck. In other embodiments, anadditional RF of about 1,000 watts at about 2 MHz is also delivered tothe electrostatic chuck thus generating a dual-bias plasma at thesubstrate level.

Embodiments described and discussed herein will be discussed inreference to a plasma-enhanced chemical vapor deposition (PE-CVD)process that can be carried out using any suitable thin film depositionsystem. Examples of suitable systems include the CENTURA® systems whichmay use a DXZ® processing chamber, PRECISION 5000® systems, PRODUCER®systems, PRODUCER® GT™ systems, PRODUCER® XP Precision™ systems,PRODUCER® SE™ systems, Sym3® processing chamber, and Mesa™ processingchamber, all of which are commercially available from Applied Materials,Inc., of Santa Clara, Calif. Other tools capable of performing PE-CVDprocesses may also be adapted to benefit from the embodiments describedherein. In addition, any system enabling the PE-CVD processes describedherein can be used to advantage. The apparatus description describedherein is illustrative and should not be construed or interpreted aslimiting the scope of the embodiments described herein.

In one or more embodiments, the substrate containing the stresseddiamond-like carbon film is further exposed to one or more thermalannealing processes to convert the stressed diamond-like carbon film toa reduced-stress diamond-like carbon film, as described and discussedherein. In some embodiments, the substrate containing the stresseddiamond-like carbon film can be thermally annealed within the sameprocess chamber (e.g., plasma process chamber) as deposited in. That is,the stressed diamond-like carbon film can be deposited and then annealedin the same process chamber to produce the reduced-stress diamond-likecarbon film.

In other embodiments, the substrate containing the stressed diamond-likecarbon film is transferred from a first process chamber (e.g., plasmaprocess chamber) to a second process chamber (e.g., thermal annealingchamber) and then exposed to the thermal annealing process to convertthe stressed diamond-like carbon film to the reduced-stress diamond-likecarbon film. For example, the fabrication process can include removingthe substrate containing the stressed diamond-like carbon film from thefirst process chamber, positioning the substrate containing the stresseddiamond-like carbon film in a thermal annealing chamber, heating thestressed diamond-like carbon film to produce the reduced-stressdiamond-like carbon film during the thermal annealing process, and thenremoving the substrate containing the reduced-stress diamond-like carbonfilm from the thermal annealing chamber.

The stressed diamond-like carbon film, the substrate, and/or the processchamber is heated at a temperature of about 200° C., about 250° C.,about 300° C., about 350° C., about 375° C., about 390° C., or about400° C. to about 410° C., about 425° C., about 450° C., about 475° C.,about 500° C., about 550° C., about 600° C., about 650° C., about 700°C., or about 800° C. to produce the reduced-stress diamond-like carbonfilm during the thermal annealing process. For example, the stresseddiamond-like carbon film, the substrate, and/or the process chamber isheated at a temperature of about 200° C. to about 800° C., about 200° C.to about 700° C., about 200° C. to about 600° C., about 200° C. to about500° C., about 200° C. to about 450° C., about 200° C. to about 400° C.,about 200° C. to about 350° C., about 200° C. to about 300° C., about300° C. to about 600° C., about 300° C. to about 500° C., about 300° C.to about 450° C., about 300° C. to about 400° C., about 300° C. to about350° C., about 350° C. to about 600° C., about 350° C. to about 500° C.,about 350° C. to about 450° C., about 350° C. to about 420° C., about350° C. to about 400° C., about 350° C. to about 380° C., about 380° C.to about 420° C., or about 390° C. to about 410° C. to produce thereduced-stress diamond-like carbon film during the thermal annealingprocess.

The stressed diamond-like carbon film, the substrate, and/or the processchamber is heated for about 15 seconds, about 30 seconds, about 1minute, about 1.5 minutes, about 2 minutes, about 3 minutes, about 4minutes, or about 5 minutes to about 6 minutes, about 8 minutes, about10 minutes, about 12 minutes, about 15 minutes, about 20 minutes, about30 minutes, about 40 minutes, about 50 minutes, about 60 minutes, about75 minutes, about 90 minutes, or longer to produce the reduced-stressdiamond-like carbon film during the thermal annealing process. Forexample, the stressed diamond-like carbon film, the substrate, and/orthe process chamber is heated for about 15 seconds to about 90 minutes,about 15 seconds to about 75 minutes, about 15 seconds to about 60minutes, about 15 seconds to about 45 minutes, about 15 seconds to about30 minutes, about 15 seconds to about 20 minutes, about 15 seconds toabout 10 minutes, about 15 seconds to about 5 minutes, about 15 secondsto about 3 minutes, about 15 seconds to about 1 minute, about 15 secondsto about 30 seconds, about 1 minute to about 90 minutes, about 1 minuteto about 75 minutes, about 1 minute to about 60 minutes, about 1 minuteto about 45 minutes, about 1 minute to about 30 minutes, about 1 minuteto about 20 minutes, about 1 minute to about 10 minutes, about 1 minuteto about 5 minutes, about 1 minute to about 3 minutes, about 3 minutesto about 90 minutes, about 3 minutes to about 75 minutes, about 3minutes to about 60 minutes, about 3 minutes to about 45 minutes, about3 minutes to about 30 minutes, about 3 minutes to about 20 minutes,about 3 minutes to about 10 minutes, about 3 minutes to about 8 minutes,about 3 minutes to about 5 minutes, about 4 minutes to about 8 minutes,or about 4 minutes to about 6 minutes to produce the reduced-stressdiamond-like carbon film during the thermal annealing process.

In one or more examples, the stressed diamond-like carbon film, thesubstrate, and/or the process chamber is heated at a temperature ofabout 200° C. to about 600° C. for about 15 seconds to about 60 minutesto produce the reduced-stress diamond-like carbon film during thethermal annealing process. In some examples, the stressed diamond-likecarbon film, the substrate, and/or the process chamber is heated at atemperature of about 300° C. to about 500° C. for about 2 minutes toabout 15 minutes to produce the reduced-stress diamond-like carbon filmduring the thermal annealing process. In other examples, the stresseddiamond-like carbon film, the substrate, and/or the process chamber isheated at a temperature of about 350° C. to about 450° C. for about 3minutes to about 8 minutes to produce the reduced-stress diamond-likecarbon film during the thermal annealing process.

The substrate containing the stressed diamond-like carbon film ispositioned or otherwise disposed within a process chamber during thethermal annealing process. The process chamber can be or include aplasma process chamber, a thermal annealing process chamber, a vacuumchamber, a deposition chamber (e.g., CVD chamber), or other types ofchambers which can be used to thermally heat the substrate. Theprocessing volume with in the process chamber can be under a vacuumand/or an environment containing a process gas or an annealing gasduring the thermal annealing process. Exemplary process gas or annealinggas can be or include nitrogen (N₂), argon, helium, neon, or anycombination thereof.

The processing volume with in the process chamber can have a pressure ofabout 0.5 mTorr, about 1 mTorr, about 5 mTorr, about 10 mTorr, about 50mTorr, about 100 mTorr, or about 500 mTorr to about 800 mTorr, about 1Torr, about 2 Torr, about 5 Torr, about 8 Torr, about 10 Torr, about 20Torr, about 50 Torr, or about 100 Torr during the thermal annealingprocess. For example, the processing volume with in the process chambercan have a pressure of about 5 mTorr to about 100 Torr, about 10 mTorrto about 100 Torr, about 100 mTorr to about 100 Torr, about 500 mTorr toabout 100 Torr, about 1 Torr to about 100 Torr, about 5 Torr to about100 Torr, about 10 Torr to about 100 Torr, about 25 Torr to about 100Torr, about 50 Torr to about 100 Torr, about 0.5 mTorr to about 20 Torr,about 5 mTorr to about 20 Torr, about 10 mTorr to about 20 Torr, about100 mTorr to about 20 Torr, about 500 mTorr to about 20 Torr, about 1Torr to about 20 Torr, about 5 Torr to about 20 Torr, about 10 Torr toabout 20 Torr, about 0.5 mTorr to about 1 Torr, about 5 mTorr to about 1Torr, about 10 mTorr to about 1 Torr, about 100 mTorr to about 1 Torr,or about 500 mTorr to about 1 Torr during the thermal annealing process.

The thermal annealing process greatly reduces the compressive stressfrom the diamond-like carbon film, such that much of the compressivestress of the stressed diamond-like carbon film is relaxed, lessened, orotherwise removed once converted to the reduced-stress diamond-likecarbon film. Many other properties of the stressed diamond-like carbonfilm, such as density, elastic modulus, sp³ hybridized carbon atomsconcentration, and hydrogen concentration, remain the same orsubstantially similar to the reduced-stress diamond-like carbon filmwhich is produced therefrom.

The compressive stress of reduced-stress diamond-like carbon film isless than the compressive stress of the stressed diamond-like carbonfilm from which the reduced-stress film is produced from. In someexamples, the compressive stress of reduced-stress diamond-like carbonfilm is about 25%, about 30%, about 35%, about 40%, about 45%, about50%, or about 55% to about 60%, about 65%, about 70%, about 75%, about80%, about 85%, about 90%, or about 95% less than the compressive stressof the stressed diamond-like carbon film. For example, the compressivestress of reduced-stress diamond-like carbon film is about 25% to about95%, about 25% to about 90%, about 25% to about 80%, about 25% to about75%, about 25% to about 70%, about 25% to about 60%, about 25% to about55%, about 25% to about 50%, about 25% to about 40%, about 40% to about95%, about 40% to about 90%, about 40% to about 80%, about 40% to about75%, about 40% to about 70%, about 40% to about 60%, about 40% to about55%, about 40% to about 50%, about 50% to about 95%, about 50% to about90%, about 50% to about 80%, about 50% to about 75%, about 50% to about70%, about 50% to about 60%, about 60% to about 70%, about 60% to about80%, or about 60% to about 90% less than the compressive stress of thestressed diamond-like carbon film.

The stressed diamond-like carbon film can have a compressive stress of−500 MPa or greater, such as about −525 MPa, about −550 MPa, about −575MPa, about −600 MPa, about −625 MPa, or about −650 MPa to about −675MPa, about −700 MPa, about −725 MPa, about −750 MPa, about −800 MPa,about −850 MPa, about −900 MPa, about −950 MPa, about −1,000 MPa, about−1,100 MPa, about −1,200 MPa, or greater. For example, the stresseddiamond-like carbon film can have a compressive stress of −500 MPa toabout −1,200 MPa, −500 MPa to about −1,000 MPa, −500 MPa to about −900MPa, −500 MPa to about −850 MPa, −500 MPa to about −800 MPa, −500 MPa toabout −750 MPa, −500 MPa to about −725 MPa, −500 MPa to about −700 MPa,−500 MPa to about −675 MPa, −500 MPa to about −650 MPa, −500 MPa toabout −625 MPa, −500 MPa to about −600 MPa, about −600 MPa to about−1,200 MPa, about −600 MPa to about −1,000 MPa, about −600 MPa to about−900 MPa, about −600 MPa to about −850 MPa, about −600 MPa to about −800MPa, about −600 MPa to about −750 MPa, about −600 MPa to about −725 MPa,about −600 MPa to about −700 MPa, about −600 MPa to about −675 MPa,about −600 MPa to about −650 MPa, about −600 MPa to about −625 MPa,about −650 MPa to about −1,200 MPa, about −650 MPa to about −1,000 MPa,about −650 MPa to about −900 MPa, about −650 MPa to about −850 MPa,about −650 MPa to about −800 MPa, about −650 MPa to about −750 MPa,about −650 MPa to about −725 MPa, or about −650 MPa to about −700 MPa.

The reduced-stress diamond-like carbon film can have a compressivestress of less than −500 MPa, such as about −10 MPa, about −20 MPa,about −50 MPa, about −80 MPa, about −100 MPa, about −125 MPa, about −150MPa, about −175 MPa, about −200 MPa, about −225 MPa, about −250 MPa,about −275 MPa, or about −300 MPa to about −325 MPa, about −350 MPa,about −375 MPa, about −400 MPa, about −425 MPa, about −450 MPa, about−475 MPa, about −490 MPa, about −495 MPa, −499 MPa, or less than −500MPa. For example, the reduced-stress diamond-like carbon film can have acompressive stress of about −20 MPa to less than −500 MPa, about −50 MPato less than −500 MPa, about −80 MPa to less than −500 MPa, about −100MPa to less than −500 MPa, about −150 MPa to less than −500 MPa, about−200 MPa to less than −500 MPa, about −225 MPa to less than −500 MPa,about −250 MPa to less than −500 MPa, about −275 MPa to less than −500MPa, about −300 MPa to less than −500 MPa, about −325 MPa to less than−500 MPa, about −350 MPa to less than −500 MPa, about −375 MPa to lessthan −500 MPa, about −400 MPa to less than −500 MPa, about −450 MPa toless than −500 MPa, about −20 MPa to about −400 MPa, about −50 MPa toabout −400 MPa, about −80 MPa to about −400 MPa, about −100 MPa to about−400 MPa, about −150 MPa to about −400 MPa, about −200 MPa to about −400MPa, about −225 MPa to about −400 MPa, about −250 MPa to about −400 MPa,about −275 MPa to about −400 MPa, about −300 MPa to about −400 MPa,about −325 MPa to about −400 MPa, about −350 MPa to about −400 MPa,about −375 MPa to about −400 MPa, about −20 MPa to about −300 MPa, about−50 MPa to about −300 MPa, about −80 MPa to about −300 MPa, about −100MPa to about −300 MPa, about −150 MPa to about −300 MPa, about −200 MPato about −300 MPa, about −225 MPa to about −300 MPa, about −250 MPa toabout −300 MPa, or about −275 MPa to about −300 MPa.

In one or more examples, the stressed diamond-like carbon film has acompressive stress of about −600 MPa to about −1,000 MPa, and onceconverted, the reduced-stress diamond-like carbon film has a compressivestress of about −20 MPa to about −400 MPa or about −150 MPa to about−400 MPa. In some examples, the stressed diamond-like carbon film has acompressive stress of about −650 MPa to about −900 MPa, and onceconverted, the reduced-stress diamond-like carbon film has a compressivestress of about −50 MPa to about −350 MPa or about −200 MPa to about−350 MPa. In other examples, the stressed diamond-like carbon film has acompressive stress of about −700 MPa to about −850 MPa, and onceconverted, the reduced-stress diamond-like carbon film has a compressivestress of about −100 MPa to about −325 MPa or about −250 MPa to about−325 MPa.

In some embodiments, hydrogen radical are fed through an RPS, whichleads to selective etching of sp² hybridized carbon atoms thusincreasing the sp³ hybridized carbon atom fraction of the film further,thus further increasing the etch selectivity. The high etch selectivityof the reduced-stress diamond-like carbon film is achieved by havinggreater density and modulus than current generation films. Not to bebound by theory but it is believed that the greater density and modulusare a result of the high content of sp³ hybridized carbon atoms in thereduced-stress diamond-like carbon film, which in turn may be achievedby a combination of low pressure and plasma power.

Each of the stressed diamond-like carbon film and the reduced-stressdiamond-like carbon film can independently have a concentration orpercentage of sp³ hybridized carbon atoms (e.g., a sp³ hybridized carbonatom content) that is at least 40 atomic percent (at %), about 45 at %,about 50 at %, about 55 at %, or about 58 at % to about 60 at %, about65 at %, about 70 at %, about 75 at %, about 80 at %, about 85 at %,about 88 at %, about 90 at %, about 92 at %, or about 95 at %, based onthe total amount of carbon atoms in the respective diamond-like carbonfilm. For example, each of the stressed diamond-like carbon film and thereduced-stress diamond-like carbon film can independently have aconcentration or percentage of sp³ hybridized carbon atoms that is atleast 40 at % to about 95 at %, about 45 at % to about 95 at %, about 50at % to about 95 at %, about 50 at % to about 90 at %, about 50 at % toabout 85 at %, about 50 at % to about 80 at %, about 50 at % to about 75at %, about 50 at % to about 70 at %, about 50 at % to about 65 at %,about 55 at % to about 75 at %, about 55 at % to about 70 at %, about 55at % to about 65 at %, about 55 at % to about 60 at %, about 60 at % toabout 80 at %, about 60 at % to about 75 at %, about 60 at % to about 70at %, about 60 at % to about 65 at %, about 65 at % to about 95 at %,about 65 at % to about 90 at %, about 65 at % to about 85 at %, about 65at % to about 80 at %, about 65 at % to about 75 at %, about 65 at % toabout 70 at %, about 65 at % to about 68 at %, about 75 at % to about 95at %, about 75 at % to about 90 at %, about 75 at % to about 85 at %,about 75 at % to about 80 at %, or about 75 at % to about 78 at %, basedon the total amount of carbon atoms in the respective diamond-likecarbon film.

In some embodiments, each of the stressed diamond-like carbon film andthe reduced-stress diamond-like carbon film can independently have aconcentration or percentage of sp² hybridized carbon atoms (e.g., a sp²hybridized carbon atom content) that is less than 60 at %, such as lessthan 55 at % or less than 50 at %. Each of the stressed diamond-likecarbon film and the reduced-stress diamond-like carbon film canindependently have a concentration or percentage of sp² hybridizedcarbon atoms that is about 5 at %, about 10 at %, about 15 at %, about20 at %, about 25 at %, about 28 at %, or about 30 at % to about 32 at%, about 35 at %, about 36 at %, about 38 at %, about 40 at %, about 45at %, about 50 at %, about 55 at %, or about 60 at %, based on the totalamount of carbon atoms in the respective diamond-like carbon film. Forexample, each of the stressed diamond-like carbon film and thereduced-stress diamond-like carbon film can independently have aconcentration or percentage of sp² hybridized carbon atoms that is about5 at % to about 60 at %, about 5 at % to about 50 at %, about 5 at % toabout 45 at %, about 5 at % to about 40 at %, about 5 at % to about 38at %, about 5 at % to about 36 at %, about 5 at % to about 35 at %,about 5 at % to about 32 at %, about 5 at % to about 30 at %, about 5 at% to about 25 at %, about 5 at % to about 20 at %, about 5 at % to about15 at %, about 5 at % to about 10 at %, about 20 at % to about 60 at %,about 20 at % to about 50 at %, about 20 at % to about 45 at %, about 20at % to about 40 at %, about 20 at % to about 38 at %, about 20 at % toabout 36 at %, about 20 at % to about 35 at %, about 20 at % to about 32at %, about 20 at % to about 30 at %, about 20 at % to about 25 at %,about 20 at % to about 22 at %, about 30 at % to about 60 at %, about 30at % to about 50 at %, about 30 at % to about 45 at %, about 30 at % toabout 40 at %, about 30 at % to about 38 at %, about 30 at % to about 36at %, about 30 at % to about 35 at %, about 30 at % to about 32 at %,about 32 at % to about 38 at %, about 32 at % to about 36 at %, about 32at % to about 34 at %, about 34 at % to about 38 at %, or about 34 at %to about 36 at %, based on the total amount of carbon atoms in therespective diamond-like carbon film.

Each of the stressed diamond-like carbon film and the reduced-stressdiamond-like carbon film independently has a density of greater than 1.5g/cc (grams per cubic centimeter (cm³)), such as about 1.55 g/cc, about1.6 g/cc, about 1.65 g/cc, or about 1.68 g/cc to about 1.7 g/cc, about1.72 g/cc, about 1.75 g/cc, about 1.78 g/cc, about 1.8 g/cc, about 1.85g/cc, about 1.9 g/cc, about 1.95 g/cc, about 1.98 g/cc, about 2 g/cc,about 2.05 g/cc, about 2.1 g/cc, or greater. For example, each of thestressed diamond-like carbon film and the reduced-stress diamond-likecarbon film independently has a density of greater than 1.5 g/cc toabout 2.1 g/cc, greater than 1.5 g/cc to about 2.05 g/cc, greater than1.5 g/cc to about 2 g/cc, greater than 1.5 g/cc to about 1.9 g/cc,greater than 1.5 g/cc to about 1.85 g/cc, greater than 1.5 g/cc to about1.8 g/cc, greater than 1.5 g/cc to about 1.78 g/cc, greater than 1.5g/cc to about 1.75 g/cc, greater than 1.5 g/cc to about 1.72 g/cc,greater than 1.5 g/cc to about 1.7 g/cc, greater than 1.5 g/cc to about1.68 g/cc, greater than 1.5 g/cc to about 1.65 g/cc, greater than 1.5g/cc to about 1.6 g/cc, about 1.6 g/cc to about 2.1 g/cc, about 1.6 g/ccto about 2.05 g/cc, about 1.6 g/cc to about 2 g/cc, about 1.6 g/cc toabout 1.9 g/cc, about 1.6 g/cc to about 1.85 g/cc, about 1.6 g/cc toabout 1.8 g/cc, about 1.6 g/cc to about 1.78 g/cc, about 1.6 g/cc toabout 1.75 g/cc, about 1.6 g/cc to about 1.72 g/cc, about 1.6 g/cc toabout 1.7 g/cc, about 1.6 g/cc to about 1.68 g/cc, about 1.6 g/cc toabout 1.65 g/cc, about 1.68 g/cc to about 2.1 g/cc, about 1.68 g/cc toabout 2.05 g/cc, about 1.68 g/cc to about 2 g/cc, about 1.68 g/cc toabout 1.9 g/cc, about 1.68 g/cc to about 1.85 g/cc, about 1.68 g/cc toabout 1.8 g/cc, about 1.68 g/cc to about 1.78 g/cc, about 1.68 g/cc toabout 1.75 g/cc, about 1.68 g/cc to about 1.72 g/cc, about 1.68 g/cc toabout 1.7 g/cc, about 1.7 g/cc to about 1.75 g/cc, about 1.7 g/cc toabout 1.72 g/cc, about 1.55 g/cc to less than 2 g/cc, about 1.6 g/cc toless than 2 g/cc, about 1.65 g/cc to less than 2 g/cc, about 1.68 g/ccto less than 2 g/cc, about 1.7 g/cc to less than 2 g/cc, about 1.72 g/ccto less than 2 g/cc, about 1.75 g/cc to less than 2 g/cc, or about 1.8g/cc to less than 2 g/cc.

Each of the stressed diamond-like carbon film and the reduced-stressdiamond-like carbon film can independently have a thickness of about 5Å, about 10 Å, about 50 Å, about 100 Å, about 150 Å, about 200 Å, orabout 300 Å to about 400 Å, about 500 Å, about 600 Å, about 700 Å, about800 Å, about 1,000 Å, about 2,000 Å, about 3,000 Å, about 5,000 Å, about6,000 Å, about 8,000 Å, about 10,000 Å, about 15,000 Å, about 20,000 Å,or thicker. For example, each of the stressed diamond-like carbon filmand the reduced-stress diamond-like carbon film can independently have athickness of about 5 Å to about 20,000 Å, about 5 Å to about 10,000 Å,about 5 Å to about 5,000 Å, about 5 Å to about 3,000 Å, about 5 Å toabout 2,000 Å, about 5 Å to about 1,000 Å, about 5 Å to about 500 Å,about 5 Å to about 200 Å, about 5 Å to about 100 Å, about 5 Å to about50 Å, about 200 Å to about 20,000 Å, about 200 Å to about 10,000 Å,about 200 Å to about 6,000 Å, about 200 Å to about 5,000 Å, about 200 Åto about 3,000 Å, about 200 Å to about 2,000 Å, about 200 Å to about1,000 Å, about 200 Å to about 500 Å, about 600 Å to about 3,000 Å, about600 Å to about 2,000 Å, about 600 Å to about 1,500 Å, about 600 Å toabout 1,000 Å, about 600 Å to about 800 Å, about 1,000 Å to about 20,000Å, about 1,000 Å to about 10,000 Å, about 1,000 Å to about 5,000 Å,about 1,000 Å to about 3,000 Å, about 1,000 Å to about 2,000 Å, about2,000 Å to about 20,000 Å, or about 2,000 Å to about 3,000 Å.

Each of the stressed diamond-like carbon film and the reduced-stressdiamond-like carbon film can independently have a refractive index orn-value (n (at 633 nm)) of greater than 2, such as about 2.1, about 2.2,about 2.3, about 2.4 or about 2.5 to about 2.6, about 2.7, about 2.8,about 2.9, or about 3. For example, each of the stressed diamond-likecarbon film and the reduced-stress diamond-like carbon film canindependently have a refractive index or n-value (n (at 633 nm)) ofgreater than 2 to about 3, greater than 2 to about 2.8, greater than 2to about 2.5, greater than 2 to about 2.3, about 2.1 to about 3, about2.1 to about 2.8, about 2.1 to about 2.5, about 2.1 to about 2.3, about2.3 to about 3, about 2.3 to about 2.8, or about 2.3 to about 2.5.

Each of the stressed diamond-like carbon film and the reduced-stressdiamond-like carbon film can independently have an extinctioncoefficient or k-value (K (at 633 nm)) of greater than 0.1, such asabout 0.15, about 0.2, about 0.25, or about 0.3. For example, each ofthe stressed diamond-like carbon film and the reduced-stressdiamond-like carbon film can independently have an extinctioncoefficient or k-value (K (at 633 nm)) of greater than 0.1 to about 0.3,greater than 0.1 to about 0.25, greater than 0.1 to about 0.2, greaterthan 0.1 to about 0.15, about 0.2 to about 0.3, or about 0.2 to about0.25.

Each of the stressed diamond-like carbon film and the reduced-stressdiamond-like carbon film can independently have an elastic modulus ofgreater than 50 GPa or greater than 60 GPa, such as about 65 GPa, about70 GPa, about 75 GPa, about 90 GPa, about 100 GPa, about 125 GPa, orabout 150 GPa to about 175 GPa, about 200 GPa, about 250 GPa, about 275GPa, about 300 GPa, about 350 GPa, or about 400 GPa. For example, eachof the stressed diamond-like carbon film and the reduced-stressdiamond-like carbon film can independently have an elastic modulus ofgreater than 60 GPa to about 400 GPa, greater than 60 GPa to about 350GPa, greater than 60 GPa to about 300 GPa, greater than 60 GPa to about250 GPa, greater than 60 GPa to about 200 GPa, greater than 60 GPa toabout 150 GPa, greater than 60 GPa to about 125 GPa, greater than 60 GPato about 100 GPa, greater than 60 GPa to about 80 GPa, about 65 GPa toabout 400 GPa, about 65 GPa to about 350 GPa, about 65 GPa to about 300GPa, about 65 GPa to about 250 GPa, about 65 GPa to about 200 GPa, about65 GPa to about 150 GPa, about 65 GPa to about 125 GPa, about 65 GPa toabout 100 GPa, about 65 GPa to about 80 GPa, about 80 GPa to about 400GPa, about 80 GPa to about 350 GPa, about 80 GPa to about 300 GPa, about80 GPa to about 250 GPa, about 80 GPa to about 200 GPa, about 80 GPa toabout 150 GPa, about 80 GPa to about 125 GPa, or about 80 GPa to about100 GPa. In one or more examples, each of the stressed diamond-likecarbon film and the reduced-stress diamond-like carbon film canindependently have the aforementioned elastic modulus and have athickness of about 600 {acute over (Å)}.

In some embodiments, the reduced-stress diamond-like carbon film is anunderlayer for an extreme ultraviolet (“EUV”) lithography process. Insome examples, the reduced-stress diamond-like carbon film is anunderlayer for an EUV lithography process and has an sp³ hybridizedcarbon atom content of about 40% to about 90% based on the total amountof carbon atoms in the film, a density of greater than 1.5 g/cc to about1.9 g/cc, and an elastic modulus that is greater than or about 60 GPa toabout 150 GPa or about 200 GPa.

FIG. 1A depicts a schematic illustration of a substrate processingsystem 132 that can be used to perform stressed diamond-like carbon filmdeposition in accordance with embodiments described herein. Thesubstrate processing system 132 includes a process chamber 100 coupledto a gas panel 130 and a controller 110. The process chamber 100generally includes a top wall 124, a sidewall 101 and a bottom wall 122that define a processing volume 126. A substrate support assembly 146 isprovided in the processing volume 126 of the process chamber 100. Thesubstrate support assembly 146 generally includes an electrostatic chuck150 supported by a stem 160. The electrostatic chuck 150 may betypically fabricated from aluminum, ceramic, and other suitablematerials. The electrostatic chuck 150 may be moved in a verticaldirection inside the process chamber 100 using a displacement mechanism(not shown).

A vacuum pump 102 is coupled to a port formed in the bottom of theprocess chamber 100. The vacuum pump 102 is used to maintain a desiredgas pressure in the process chamber 100. The vacuum pump 102 alsoevacuates post-processing gases and by-products of the process from theprocess chamber 100.

The substrate processing system 132 may further include additionalequipment for controlling the chamber pressure, for example, valves(e.g., throttle valves and isolation valves) positioned between theprocess chamber 100 and the vacuum pump 102 to control the chamberpressure.

A gas distribution assembly 120 having a plurality of apertures 128 isdisposed on the top of the process chamber 100 above the electrostaticchuck 150. The apertures 128 of the gas distribution assembly 120 areutilized to introduce process gases (e.g., deposition gas, dilution gas,carrier gas, purge gas) into the process chamber 100. The apertures 128may have different sizes, number, distributions, shape, design, anddiameters to facilitate the flow of the various processing gases fordifferent process requirements. The gas distribution assembly 120 isconnected to the gas panel 130 that allows various gases to supply tothe processing volume 126 during processing. A plasma is formed from theprocessing gas mixture exiting the gas distribution assembly 120 toenhance thermal decomposition of the processing gases resulting in thedeposition of material on a surface 191 of the substrate 190.

The gas distribution assembly 120 and the electrostatic chuck 150 mayform a pair of spaced apart electrodes in the processing volume 126. Oneor more RF power source 140 provide a bias potential through a matchingnetwork 138, which is optional, to the gas distribution assembly 120 tofacilitate generation of plasma between the gas distribution assembly120 and the electrostatic chuck 150. Alternatively, the RF power source140 and the matching network 138 may be coupled to the gas distributionassembly 120, the electrostatic chuck 150, or coupled to both the gasdistribution assembly 120 and the electrostatic chuck 150, or coupled toan antenna (not shown) disposed exterior to the process chamber 100. Inone or more examples, the RF power source 140 may produce power at afrequency of about 350 KHz, about 2 MHz, about 13.56 MHz, about 27 MHz,about 40 MHz, about 60 MHz, or about 100 MHz. In some examples, the RFpower source 140 may provide power of about 100 watts to about 3,000watts at a frequency of about 50 kHz to about 13.6 MHz. In otherexamples, the RF power source 140 may provide power of about 500 wattsto about 1,800 watts at a frequency of about 50 kHz to about 13.6 MHz.

The controller 110 includes a central processing unit (CPU) 112, amemory 116, and a support circuit 114 utilized to control the processsequence and regulate the gas flows from the gas panel 130. The CPU 112may be of any form of a general-purpose computer processor that may beused in an industrial setting. The software routines can be stored inthe memory 116, such as random access memory, read only memory, floppy,or hard disk drive, or other form of digital storage. The supportcircuit 114 is conventionally coupled to the CPU 112 and may includecache, clock circuits, input/output systems, power supplies, and thelike. Bi-directional communications between the controller 110 and thevarious components of the substrate processing system 132 are handledthrough numerous signal cables collectively referred to as signal buses118, some of which are illustrated in FIG. 1A.

FIG. 1B depicts a schematic cross-sectional view of another substrateprocessing system 180 that can be used for the practice of embodimentsdescribed herein. The substrate processing system 180 is similar to thesubstrate processing system 132 of FIG. 1A, except that the substrateprocessing system 180 is configured to flow processing gases from gaspanel 130 across the surface 191 of the substrate 190 via the sidewall101. In addition, the gas distribution assembly 120 depicted in FIG. 1Ais replaced with an electrode 182. The electrode 182 may be configuredfor secondary electron generation. In one or more embodiments, theelectrode 182 is a silicon-containing electrode.

FIG. 2 depicts a schematic cross-sectional view of the substrate supportassembly 146 used in the processing systems of FIG. 1A and FIG. 1B thatcan be used for the practice of embodiments described herein. Referringto FIG. 2, the electrostatic chuck 150 may include a heater element 170suitable for controlling the temperature of a substrate 190 supported onan upper surface 192 of the electrostatic chuck 150. The heater element170 may be embedded in the electrostatic chuck 150. The electrostaticchuck 150 may be resistively heated by applying an electric current froma heater power source 106 to the heater element 170. The heater powersource 106 may be coupled through an RF filter 216. The RF filter 216may be used to protect the heater power source 106 from RF energy. Theheater element 170 may be made of a nickel-chromium wire encapsulated ina nickel-iron-chromium alloy (e.g., INCOLOY® alloy) sheath tube. Theelectric current supplied from the heater power source 106 is regulatedby the controller 110 to control the heat generated by the heaterelement 170, thus maintaining the substrate 190 and the electrostaticchuck 150 at a substantially constant temperature during filmdeposition. The supplied electric current may be adjusted to selectivelycontrol the temperature of the electrostatic chuck 150 to be about −50°C. to about 600° C.

Referring to FIG. 1, a temperature sensor 172, such as a thermocouple,may be embedded in the electrostatic chuck 150 to monitor thetemperature of the electrostatic chuck 150 in a conventional manner. Themeasured temperature is used by the controller 110 to control the powersupplied to the heater element 170 to maintain the substrate at adesired temperature.

The electrostatic chuck 150 includes a chucking electrode 210, which maybe a mesh of a conductive material. The chucking electrode 210 may beembedded in the electrostatic chuck 150. The chucking electrode 210 iscoupled to a chucking power source 212 that, when energized,electrostatically clamps the substrate 190 to the upper surface 192 ofthe electrostatic chuck 150.

The chucking electrode 210 may be configured as a monopolar or bipolarelectrode, or have another suitable arrangement. The chucking electrode210 may be coupled through an RF filter 214 to the chucking power source212, which provides direct current (DC) power to electrostaticallysecure the substrate 190 to the upper surface 192 of the electrostaticchuck 150. The RF filter 214 prevents RF power utilized to form plasmawithin the process chamber 100 from damaging electrical equipment orpresenting an electrical hazard outside the chamber. The electrostaticchuck 150 may be fabricated from a ceramic material, such as aluminumnitride or aluminum oxide (e.g., alumina). Alternately, theelectrostatic chuck 150 may be fabricated from a polymer, such aspolyimide, polyetheretherketone (PEEK), polyaryletherketone (PAEK), andthe like.

A power application system 220 is coupled to the substrate supportassembly 146. The power application system 220 may include the heaterpower source 106, the chucking power source 212, a first radio frequency(RF) power source 230, and a second RF power source 240. The powerapplication system 220 may additionally include the controller 110, anda sensor device 250 that is in communication with the controller 110 andboth of the first RF power source 230 and the second RF power source240. The controller 110 may also be utilized to control the plasma fromthe processing gas by application of RF power from the first RF powersource 230 and the second RF power source 240 in order to deposit alayer of material on the substrate 190.

As described above, the electrostatic chuck 150 includes the chuckingelectrode 210 that may function in one aspect to chuck the substrate 190while also functioning as a first RF electrode. The electrostatic chuck150 may also include a second RF electrode 260, and together with thechucking electrode 210, may apply RF power to tune the plasma. The firstRF power source 230 may be coupled to the second RF electrode 260 whilethe second RF power source 240 may be coupled to the chucking electrode210. A first matching network and a second matching network may beprovided for the first RF power source 230 and the second RF powersource 240, respectively. The second RF electrode 260 may be a solidmetal plate of a conductive material as shown. Alternatively, the secondRF electrode 260 may be a mesh of conductive material.

The first RF power source 230 and the second RF power source 240 mayproduce power at the same frequency or a different frequency. In one ormore embodiments, one or both of the first RF power source 230 and thesecond RF power source 240 may independently produce power at afrequency from about 350 KHz to about 100 MHz (e.g., 350 KHz, 2 MHz,13.56 MHz, 27 MHz, 40 MHz, 60 MHz, or 100 MHz). In one or moreembodiments, the first RF power source 230 may produce power at afrequency of 13.56 MHz and the second RF power source 240 may producepower at a frequency of 2 MHz, or vice versa. RF power from one or bothof the first RF power source 230 and second RF power source 240 may bevaried in order to tune the plasma. For example, the sensor device 250may be used to monitor the RF energy from one or both of the first RFpower source 230 and the second RF power source 240. Data from thesensor device 250 may be communicated to the controller 110, and thecontroller 110 may be utilized to vary power applied by the first RFpower source 230 and the second RF power source 240.

In one or more embodiments, the electrostatic chuck 150 has the chuckingelectrode 210 and an RF electrode separate from each other, and thefirst RF bias can be applied to the RF electrode 260 and the second RFbias can be applied to the chucking electrode 210. In one or moreexamples, the first RF bias is provided at a power of about 10 watts toabout 3,000 watts at a frequency of about 350 KHz to about 100 MHz andthe second RF bias is provided at a power of about 10 watts to about3,000 watts at a frequency of about 350 KHz to about 100 MHz. In otherexamples, the first RF bias is provided at a power of about 2,500 wattsto about 3,000 watts at a frequency of about 13.56 MHz and the second RFbias is provided at a power of about 800 watts to about 1,200 watts at afrequency of about 2 MHz.

In one or more embodiments, a deposition gas containing one or morehydrocarbon compounds may be flowed or otherwise introduced into theprocessing volume of the process chamber, such as a PE-CVD chamber. Thehydrocarbon compound and the dilution gas, if used, can be independentlyflowed or introduced into the processing volume. In some examples, oneor more substrates are positioned on an electrostatic chuck in theprocess chamber. The electrostatic chuck can have a chucking electrodeand an RF electrode separate from each other. A plasma may be ignited orotherwise generated at or near the substrate (e.g., substrate level) byapplying a first RF bias to the RF electrode and a second RF bias to thechucking electrode. The stressed diamond-like carbon film is depositedor otherwise formed on the substrate. In some embodiments, a patternedphotoresist layer may be deposited or otherwise formed over the stresseddiamond-like carbon film, the stressed diamond-like carbon film isetched or otherwise formed in a pattern corresponding with the patternedphotoresist layer, and the pattern is etched or otherwise formed intothe substrate. In other embodiments, the stressed diamond-like carbonfilm is converted to the reduced-stress diamond-like carbon film, then apatterned photoresist layer may be deposited or otherwise formed overthe reduced-stress diamond-like carbon film, the reduced-stressdiamond-like carbon film is etched or otherwise formed in a patterncorresponding with the patterned photoresist layer, and the pattern isetched or otherwise formed into the substrate.

In general, the following exemplary deposition process parameters may beused to form the stressed diamond-like carbon film. The substratetemperature may range of about −50° C. to about 350° C. (e.g., about−40° C. to about 100° C., about 10° C. to about 100° C., or about 10° C.to about 50° C.). The chamber pressure may range from a chamber pressureof about 0.5 mTorr to about 10 Torr (e.g., about 2 mTorr to about 50mTorr, or about 2 mTorr to about 10 mTorr). The flow rate of thehydrocarbon compound may be about 20 sccm to about 5,000 sccm (e.g.,about 50 sccm to about 1,000 sccm, about 100 sccm to about 200 sccm, orabout 150 sccm to about 200 sccm). The flow rate of a dilution gas orpurge gas (e.g., He) may be about 1 sccm to about 3,000 sccm (e.g.,about 5 sccm to about 500 sccm, about 10 sccm to about 150 sccm, orabout 20 sccm to about 100 sccm). The stressed diamond-like carbon filmmay be deposited to a thickness of about 200 Å and about 6,000 Å (e.g.,about 300 Å to about 5,000 Å; about 400 Å to about 800 Å; about 2,000 Åand about 3,000 Å, or about 5 Å to about 200 Å—depending onapplication). In one or more examples, these process parameters provideexamples of process parameters for a 300 mm substrate in a depositionchamber commercially available from Applied Materials, Inc. of SantaClara, Calif.

FIG. 3 depicts a flow diagram of a method 300 for forming areduced-stress diamond-like carbon film on a film stack disposed on asubstrate in accordance with one embodiment of the present disclosure.The reduced-stress diamond-like carbon film formed on a film stack maybe utilized, for example, as a hardmask to form stair-like structures inthe film stack. FIGS. 4A-4B are schematic cross-sectional viewsillustrating a sequence for forming a reduced-stress diamond-like carbonfilm on a film stack disposed on a substrate according to the method300. Although the method 300 is described below with reference to ahardmask layer that may be formed on a film stack utilized tomanufacture stair-like structures in the film stack for threedimensional semiconductor devices, the method 300 may also be used toadvantage in other device manufacturing applications. Further, it shouldalso be understood that the operations depicted in FIG. 3 may beperformed simultaneously and/or in a different order than the orderdepicted in FIG. 3.

The method 300 begins at operation 310 by positioning a substrate, suchas a substrate 402 depicted in FIG. 4A, into a processing volume of aprocess chamber, such as the process chamber 100 depicted in FIG. 1A orFIG. 1B. The substrate 402 may be substrate 190 depicted in FIG. 1A,FIG. 1B, and FIG. 2. The substrate 402 may be positioned on anelectrostatic chuck, for example, the upper surface 192 of theelectrostatic chuck 150. The substrate 402 may be a silicon-basedmaterial or any suitable insulating material or conductive material asneeded, having a film stack 404 disposed on the substrate 402 that maybe utilized to form a structure 400, such as stair-like structures, inthe film stack 404.

As shown in the embodiment depicted in FIG. 4A, the substrate 402 mayhave a substantially planar surface, an uneven surface, or asubstantially planar surface having a structure formed thereon. The filmstack 404 is formed on the substrate 402. In one or more embodiments,the film stack 404 may be utilized to form a gate structure, a contactstructure or an interconnection structure in a front end or back endprocess. The method 300 may be performed on the film stack 404 to formthe stair-like structures therein used in a memory structure, such asNAND structure. In one or more embodiments, the substrate 402 may be amaterial such as crystalline silicon (e.g., Si<100> or Si<111>), siliconoxide, strained silicon, silicon germanium, doped or undopedpolysilicon, doped or undoped silicon substrates and patterned ornon-patterned substrates silicon on insulator (SOI), carbon dopedsilicon oxides, silicon nitride, doped silicon, germanium, galliumarsenide, glass, sapphire. The substrate 402 may have variousdimensions, such as 200 mm, 300 mm, 450 mm, or other diametersubstrates, as well as, rectangular or square panels. Unless otherwisenoted, embodiments and examples described herein are conducted onsubstrates with a 200 mm diameter, a 300 mm diameter, or a 450 mmdiameter substrate. In the embodiment wherein a SOI structure isutilized for the substrate 402, the substrate 402 may include a burieddielectric layer disposed on a silicon crystalline substrate. In one ormore embodiments depicted herein, the substrate 402 may be a crystallinesilicon substrate.

In one or more embodiments, the film stack 404 disposed on the substrate402 may have a number of vertically stacked layers. The film stack 404may contain pairs including a first layer (shown as 408 a ₁, 408 a ₂,408 a ₃, . . . , 408 a _(n)) and a second layer (shown as 408 b ₁, 408 b₂, 408 b ₃, . . . , 408 b _(n)) repeatedly formed in the film stack 404.The pairs includes alternating first layer (shown as 408 a ₁, 408 a ₂,408 a ₃, . . . , 408 a _(n)) and second layer (shown as 408 b ₁, 408 b₂, 408 b ₃, . . . , 408 b _(n)) repeatedly formed until desired numbersof pairs of the first layers and the second layers are reached.

The film stack 404 may be a part of a semiconductor chip, such as athree-dimensional memory chip Although three repeating layers of firstlayers (shown as 408 a ₁, 408 a ₂, 408 a ₃, . . . , 408 a _(n)) andsecond layers (shown as 408 b ₁, 408 b ₂, 408 b ₃, . . . , 408 b _(n))are shown in FIGS. 4A-4B, it is noted that any desired number ofrepeating pairs of the first and the second layers may be utilized asneeded.

In one or more embodiments, the film stack 404 may be utilized to formmultiple gate structures for a three-dimensional memory chip. The firstlayers 408 a ₁, 408 a ₂, 408 a ₃, . . . , 408 a _(n), formed in the filmstack 404 may be a first dielectric layer and the second layers 408 b ₁,408 b ₂, 408 b ₃, . . . , 408 b _(n) may be a second dielectric layer.Suitable dielectric layers may be utilized to form the first layers 408a ₁, 408 a ₂, 408 a ₃, . . . , 408 a _(n) and the second layer 408 b ₁,408 b ₂, 408 b ₃, . . . , 408 b _(n) include silicon oxide, siliconnitride, silicon oxynitride, silicon carbide, silicon oxycarbide,titanium nitride, composite of oxide and nitride, at least one or moreoxide layers sandwiching a nitride layer, and combinations thereof,among others. In one or more embodiments, the dielectric layers may be ahigh-k material having a dielectric constant greater than 4. Suitableexamples of the high-k materials include hafnium oxide, zirconium oxide,titanium oxide, hafnium silicon oxide or hafnium silicate, hafniumaluminum oxide or hafnium aluminate, zirconium silicon oxide orzirconium silicate, tantalum oxide, aluminum oxide, aluminum dopedhafnium dioxide, bismuth strontium titanium (BST), and platinumzirconium titanium (PZT), dopants thereof, or any combination thereof.

In one or more examples, the first layers 408 a ₁, 408 a ₂, 408 a ₃, . .. , 408 a _(n) are silicon oxide layers and the second layers 408 b ₁,408 b ₂, 408 b ₃, . . . , 408 b _(n) are silicon nitride layers orpolysilicon layers disposed on the first layers 408 a ₁, 408 a ₂, 408 a₃, . . . , 408 a _(n). In one or more embodiments, the thickness offirst layers 408 a ₁, 408 a ₂, 408 a ₃, . . . , 408 a _(n) may becontrolled to be about 50 Å to about 1,000 Å, such as about 500 Å, andthe thickness of the each second layers 408 b ₁, 408 b ₂, 408 b ₃, . . ., 408 b _(n) may be controlled to be about 50 Å to about 1,000 Å, suchas about 500 Å. The film stack 404 may have a total thickness of about100 Å to about 2,000 Å. In one or more embodiments, a total thickness ofthe film stack 404 is about 3 microns to about 10 microns and can varyas technology advances.

It is noted that the reduced-stress diamond-like carbon film may beformed on any surfaces or any portion of the substrate 402 with orwithout the film stack 404 present on the substrate 402.

At operation 320, a chucking voltage is applied to the electrostaticchuck and the substrate 402 clamped or otherwise disposed on to theelectrostatic chuck. In one or more embodiments, where the substrate 402is positioned on the upper surface 192 of the electrostatic chuck 150,the upper surface 192 provides support and clamps the substrate 402during processing. The electrostatic chuck 150 flattens the substrate402 closely against the upper surface 192, preventing backsidedeposition. An electrical bias is provided to the substrate 402 viachucking electrode 210. The chucking electrode 210 may be in electroniccommunication with the chucking power source 212 that supplies a biasingvoltage to the chucking electrode 210. In one or more embodiments, thechucking voltage is about 10 volts to about 3,000 volts, about 100 voltsto about 2,000 volts, or about 200 volts to about 1,000 volts.

During operation 320, several process parameters may be regulated theprocess. In one embodiment suitable for processing a 300 mm substrate,the process pressure in the processing volume may be maintained at about0.1 mTorr to about 10 Torr (e.g., about 2 mTorr to about 50 mTorr; orabout 5 mTorr to about 20 mTorr). In some embodiments suitable forprocessing a 300 mm substrate, the processing temperature and/orsubstrate temperature may be maintained at about −50° C. to about 350°C. (e.g., about 0° C. to about 50° C.; or about 10° C. to about 20° C.).

In one or more embodiments, a constant chucking voltage is applied tothe substrate 402. In some embodiments, the chucking voltage may bepulsed to the electrostatic chuck 150. In other embodiments, a backsidegas may be applied to the substrate 402 while applying the chuckingvoltage to control the temperature of the substrate. Backside gases canbe or include helium, argon, neon, nitrogen (N₂), hydrogen (H₂), or anycombination thereof.

At operation 330, a plasma is generated at the substrate, such asadjacent the substrate or near the substrate level, by applying a firstRF bias to the electrostatic chuck. Plasma generated at the substratemay be generated in a plasma region between the substrate and theelectrostatic chuck. The first RF bias may be from about 10 watts toabout 3,000 watts at a frequency of about 350 KHz to about 100 MHz(e.g., about 350 KHz, about 2 MHz, about 13.56 MHz, about 27 MHz, about40 MHz, about 60 MHz, or about 100 MHz). In one or more embodiments, thefirst RF bias is provided at a power of about 2,500 watts to about 3,000watts at a frequency of about 13.56 MHz. In one or more embodiments, thefirst RF bias is provided to the electrostatic chuck 150 via the secondRF electrode 260. The second RF electrode 260 may be in electroniccommunication with the first RF power source 230 that supplies a biasingvoltage to the second RF electrode 260. In one or more embodiments, thebias power is about 10 watts to about 3,000 watts, about 2,000 watts toabout 3,000 watts, or about 2,500 watts to about 3,000 watts. The firstRF power source 230 may produce power at a frequency of about 350 KHz toabout 100 MHz (e.g., about 350 KHz, about 2 MHz, about 13.56 MHz, about27 MHz, about 40 MHz, about 60 MHz, or about 100 MHz).

In one or more embodiments, operation 330 further includes applying asecond RF bias to the electrostatic chuck. The second RF bias may befrom about 10 watts to about 3,000 watts at a frequency of about 350 KHzto about 100 MHz (e.g., about 350 KHz, about 2 MHz, about 13.56 MHz,about 27 MHz, about 40 MHz, about 60 MHz, or about 100 MHz). In someexamples, the second RF bias is provided at a power of about 800 wattsto about 1,200 watts at a frequency of about 2 MHz. In other examples,the second RF bias is provided to the substrate 402 via the chuckingelectrode 210. The chucking electrode 210 may be in electroniccommunication with second RF power source 240 that supplies a biasingvoltage to the chucking electrode 210. In one or more examples, the biaspower is about 10 watts to about 3,000 watts, about 500 watts to about1,500 watts, or about 800 watts to about 1,200 watts. The second RFpower source 240 may produce power at a frequency of about 350 KHz toabout 100 MHz (e.g., about 350 KHz, about 2 MHz, about 13.56 MHz, about27 MHz, about 40 MHz, about 60 MHz, or about 100 MHz). In one or moreembodiments, the chucking voltage supplied in operation 320 ismaintained during operation 330.

In some embodiments, during operation 330, the first RF bias is providedto the substrate 402 via the chucking electrode 210 and the second RFbias may be provided to the substrate 402 via the second RF electrode260. In one or more examples, the first RF bias is about 2,500 watts(about 13.56 MHz) and the second RF bias is about 1,000 watts (about 2MHz).

During operation 340, a deposition gas is flowed into the processingvolume 126 to form the stressed diamond-like carbon film on the filmstack. The deposition gas may be flowed from the gas panel 130 into theprocessing volume 126 either through the gas distribution assembly 120or via the sidewall 101. The deposition gas contains one or morehydrocarbon compounds. The hydrocarbon compound can be or include one,two, or more one hydrocarbon compounds in any state of matter. Thehydrocarbon compound can be any liquid or gas, but some advantages maybe realized if any of the precursors is vapor at room temperature inorder to simplify the hardware needed for material metering, control,and delivery to the processing volume.

The deposition gas may further include an inert gas, a dilution gas, anetchant gas or any combination thereof. In one or more embodiments, thechucking voltage supplied during operation 320 is maintained duringoperation 340. In some embodiments, the process conditions establishedduring operation 320 and plasma formed during operation 330 aremaintained during operation 340.

In one or more embodiments, the hydrocarbon compound is a gaseoushydrocarbon or a liquid hydrocarbon. The hydrocarbon can be or includeone or more alkanes, one or more alkenes, one or more alkynes, one ormore aromatic, or any combination thereof. In some examples, thehydrocarbon compound has a general formula C_(x)H_(y), where x has arange of 1 to about 20 and y has a range of 1 to about 20. Suitablehydrocarbon compounds include, for example, C₂H₂, C₃H₆, CH₄, C₄H₈,1,3-dimethyladamantane, bicyclo[2.2.1]hepta-2,5-diene(2,5-norbornadiene), adamantine (C₁₀H₁₆), norbornene (C₇H₁₀), or anycombination thereof. In one or more examples, ethyne is utilized due toformation of more stable intermediate species, which allows more surfacemobility.

The hydrocarbon compound can be or include one or more alkanes (e.g.,C_(n)H_(2n+2), wherein n is from 1 to 20). Suitable hydrocarboncompounds include, for example, alkanes such as methane (CH₄), ethane(C₂H₆), propane (C₃H₈), butane (C₄H₁₀) and its isomer isobutane, pentane(C₅H₁₂), hexane (C₆H₁₄) and its isomers isopentane and neopentane,hexane (C₆H₁₄) and its isomers 2-methylpentane, 3-methylpentane,2,3-dimethylbutane, and 2,2-dimethyl butane, or any combination thereof.

The hydrocarbon compound can be or include one or more alkenes (e.g.,C_(n)H_(2n), wherein n is from 1 to 20). Suitable hydrocarbon compoundsinclude, for example, alkenes such as ethylene, propylene (C₃H₆),butylene and its isomers, pentene and its isomers, and the like, dienessuch as butadiene, isoprene, pentadiene, hexadiene, or any combinationthereof. Additional suitable hydrocarbons include, for example,halogenated alkenes such as monofluoroethylene, difluoroethylenes,trifluoroethylene, tetrafluoroethylene, monochloroethylene,dichloroethylenes, trichloroethylene, tetrachloroethylene, or anycombination thereof.

The hydrocarbon compound can be or include one or more alkynes (e.g.,C_(n)H_(2n−2), wherein n is from 1 to 20). Suitable hydrocarboncompounds include, for example, alkynes such as ethyne or acetylene(C₂H₂), propyne (C₃H₄), butylene (C₄H₈), vinylacetylene, or anycombination thereof.

The hydrocarbon compound can be or include one or more aromatichydrocarbon compounds, such as benzene, styrene, toluene, xylene,ethylbenzene, acetophenone, methyl benzoate, phenyl acetate, phenol,cresol, furan, and the like, alpha-terpinene, cymene,1,1,3,3-tetramethylbutylbenzene, t-butylether, t-butylethylene,methyl-methacrylate, and t-butylfurfurylether, compounds having theformula C₃H₂ and C₅H₄, halogenated aromatic compounds includingmonofluorobenzene, difluorobenzenes, tetrafluorobenzenes,hexafluorobenzene, or any combination thereof.

In one or more embodiments, the deposition gas further contains one ormore dilution gases, one or more carrier gases, and/or one or more purgegases. Suitable dilution gases, carrier gases, and/or purge gases suchas helium (He), argon (Ar), xenon (Xe), hydrogen (H₂), nitrogen (N₂),ammonia (NH₃), nitric oxide (NO), or any combination thereof, amongothers, may be co-flowed or otherwise supplied with the deposition gasinto the processing volume 126. Argon, helium, and/or nitrogen can beused to control the density and deposition rate of the stresseddiamond-like carbon film. In some cases, the addition of N₂ and/or NH₃can be used to control the hydrogen ratio of the stressed diamond-likecarbon film, as discussed below. Alternatively, dilution gases may notbe used during the deposition.

In some embodiments, the deposition gas further contains an etchant gas.Suitable etchant gases can be or include chlorine (Cl₂), fluorine (F₂),hydrogen fluoride (HF), carbon tetrafluoride (CF₄), nitrogen trifluoride(NF₃), or any combination thereof. Not to be bound by theory, but it isbelieved that the etchant gases selectively etch sp² hybridized carbonatoms from the film thus increasing the fraction of sp³ hybridizedcarbon atoms in the film, which increases the etch selectivity of thestressed diamond-like carbon film 412.

In one or more embodiments, after the stressed diamond-like carbon film412 is deposited or otherwise formed on the substrate during operation340, the stressed diamond-like carbon film 412 is exposed to hydrogenradicals. In some embodiments, the stressed diamond-like carbon film isexposed to hydrogen radicals during the deposition process of operation340. In other embodiments, the hydrogen radicals formed in an RPS anddelivered to the processing region. Not to be bound by theory, but it isbelieved that exposing the stressed diamond-like carbon film to hydrogenradicals leads to selective etching of sp² hybridized carbon atoms thusincreasing the sp³ hybridized carbon atom fraction of the film, thusincreasing the etch selectivity.

At operation 350, after the stressed diamond-like carbon film 412 isformed on the substrate, the substrate is de-chucked. During operation350, the chucking voltage is turned-off. The reactive gases areturned-off and optionally purged from the processing chamber. In one ormore embodiments, the RF power is reduced (e.g., about 200 watt) duringoperation 350. Optionally, the controller 110 monitors impedance changeto determine whether electrostatic charges are dissipated to groundthrough the RF path. Once the substrate is de-chucked from theelectrostatic chuck, the remaining gases are purged from the processingchamber. The processing chamber is pumped down and the substrate ismoved up on the lift pins and transferred out of the process chamber.

In some alternative embodiments, before de-chucking the substrate atoperation 350, the substrate containing the stressed diamond-like carbonfilm 412 can be heated to produce the reduced-stress diamond-like carbonfilm during a thermal annealing process within the same process chamber.

In one or more embodiments, after operation 350, the substratecontaining the stressed diamond-like carbon film 412 is moved up on thelift pins and transferred out of the plasma process chamber. Atoperation 360, the substrate is introduced into another process chamber,such as a thermal annealing chamber, a vacuum chamber, a depositionchamber, or any other type of process chamber that can be used toconduct the thermal annealing process. The substrate containing thestressed diamond-like carbon film 412 is heated to a temperature ofabout 200° C. to about 600° C. for about 15 seconds to about 60 minutesto produce the reduced-stress diamond-like carbon film during thethermal annealing process.

FIG. 5 depicts a flow diagram of a method 500 of using a reduced-stressdiamond-like carbon film in accordance with one or more embodimentsdescribed and discussed herein. After the reduced-stress diamond-likecarbon film 412 is formed on the substrate, the reduced-stressdiamond-like carbon film 412 may be utilized in an etching process as apatterning mask to form a three-dimensional structure, such as a stairlike structure. The reduced-stress diamond-like carbon film 412 may bepatterned using a standard photoresist patterning techniques. Atoperation 510, a patterned photoresist (not shown) may be formed overthe reduced-stress diamond-like carbon film 412. At operation 520, thereduced-stress diamond-like carbon film 412 may be etched in a patterncorresponding with the patterned photoresist layer followed by etchingthe pattern into the substrate 402 at operation 530. At operation 540,material may be deposited into the etched portions of the substrate 402.At operation 550, the reduced-stress diamond-like carbon film 412 may beremoved using a solution containing hydrogen peroxide and sulfuric acid.One exemplary solution containing hydrogen peroxide and sulfuric acid isknown as Piranha solution or Piranha etch. The reduced-stressdiamond-like carbon film 412 may also be removed using etch chemistriescontaining oxygen and halogens (e.g., fluorine or chlorine), forexample, Cl₂/O₂, CF₄/O₂, Cl₂/O₂/CF₄. The reduced-stress diamond-likecarbon film 412 may be removed by a chemical mechanical polishing (CMP)process.

Extreme Ultraviolet (“EUV”) Patterning Schemes

The choice of underlayer is critical to preventing nanofailures (e.g.,bridging defects and spacing defects) in semiconductor devices whenusing metal-containing photoresists in extreme ultraviolet (“EUV”)patterning schemes. Conventional underlayers for EUV patterning(lithography) schemes are spin on carbon (SOC) materials. However,during patterning, metals such as tin, for example, diffuse through theSOC material leading to nanofailures in the semiconductor devices. Suchnanofailures act to reduce, degrade, and hamper semiconductorperformance.

The high-density carbon films described herein, on the other hand, havesuperior film qualities such as improved hardness and density. Suchhardness and density allow the high-density carbon film to act as astronger barrier against metal infiltration and to prevent and at aminimum, reduce nanofailures to a greater extent than the conventionalSOC films. In one or more embodiments, a reduced-stress diamond-likecarbon film for use as an underlayer for an extreme ultraviolet (“EUV”)lithography process is provided.

In one or more embodiments, a reduced-stress diamond-like carbon filmfor use as an underlayer for an EUV lithography process can be any filmdescribed herein. The reduced-stress diamond-like carbon film can havean sp³ hybridized carbon atom content of about 40% to about 90% based onthe total amount of carbon atoms in the reduced-stress diamond-likecarbon film, a compressive stress of about −20 MPa to less than −600MPa, about −150 MPa to less than −600 MPa, or about −200 MPa to lessthan −600 MPa, such as about −225 MPa to about −500 MPa or about −250MPa to about −400 MPa, an elastic modulus of greater than 60 GPa toabout 200 GPa or greater than 60 GPa to about 150 GPa, and a density ofgreater than 1.5 g/cc to about 2.1 g/cc, such as about 1.55 g/cc to lessthan 2 g/cc, for example, about 1.6 g/cc to about 1.8 g/cc, about 1.65g/cc to about 1.75 g/cc, or about 1.68 g/cc to about 1.72 g/cc.

Thus, methods and apparatuses for forming a hardmask layer, which is orcontains a reduced-stress diamond-like carbon film, which may beutilized to form stair-like structures for manufacturingthree-dimensional stacking of semiconductor devices are provided. Byutilization of the reduced-stress diamond-like carbon film as a hardmasklayer with desired robust film properties and etching selectivity, animproved dimension and profile control of the resultant structuresformed in a film stack may be obtained and the electrical performance ofthe chip devices may be enhanced in applications for three-dimensionalstacking of semiconductor devices.

In summary, some of the benefits of the present disclosure provide aprocess for depositing or otherwise forming reduced-stress diamond-likecarbon films on a substrate. Typical PE-CVD hardmask films have a verylow percent of hybridized sp³ atoms and hence low modulus and etchselectivity. In some embodiments described herein, low process pressures(less than 1 Torr) and bottom driven plasma enables fabrication of dopedfilms with about 60% or greater hybridized sp³ atoms, which results inan improvement in etch selectivity relative to previously availablehardmask films. In addition, some of the embodiments described hereinare performed at low substrate temperatures, which enable the depositionof other dielectric films at much lower temperatures than currentlypossible, opening up applications with low thermal budget that could notbe currently addressed by CVD. Additionally, some of the embodimentsdescribed herein may be used as an underlayer for an EUV lithographyprocess.

While the foregoing is directed to embodiments of the disclosure, otherand further embodiments may be devised without departing from the basicscope thereof, and the scope thereof is determined by the claims thatfollow. All documents described herein are incorporated by referenceherein, including any priority documents and/or testing procedures tothe extent they are not inconsistent with this text. As is apparent fromthe foregoing general description and the specific embodiments, whileforms of the present disclosure have been illustrated and described,various modifications can be made without departing from the spirit andscope of the present disclosure. Accordingly, it is not intended thatthe present disclosure be limited thereby. Likewise, the term“comprising” is considered synonymous with the term “including” forpurposes of United States law. Likewise whenever a composition, anelement or a group of elements is preceded with the transitional phrase“comprising”, it is understood that we also contemplate the samecomposition or group of elements with transitional phrases “consistingessentially of,” “consisting of”, “selected from the group of consistingof,” or “is” preceding the recitation of the composition, element, orelements and vice versa.

Certain embodiments and features have been described using a set ofnumerical upper limits and a set of numerical lower limits. It should beappreciated that ranges including the combination of any two values,e.g., the combination of any lower value with any upper value, thecombination of any two lower values, and/or the combination of any twoupper values are contemplated unless otherwise indicated. Certain lowerlimits, upper limits and ranges appear in one or more claims below.

1. A method of processing a substrate, comprising: flowing a depositiongas comprising a hydrocarbon compound into a processing volume of aprocess chamber having a substrate positioned on an electrostatic chuck,wherein the processing volume is maintained at a pressure of about 0.5mTorr to about 10 Torr; generating a plasma above the substrate in theprocessing volume by applying a first RF bias to the electrostatic chuckto deposit a stressed diamond-like carbon film on the substrate, whereinthe stressed diamond-like carbon film has a compressive stress of −500MPa or greater; and heating the stressed diamond-like carbon film to atemperature of about 200° C. to about 600° C. for about 15 seconds toabout 60 minutes to produce a reduced-stress diamond-like carbon filmduring a thermal annealing process, wherein the reduced-stressdiamond-like carbon film has a compressive stress of less than −500 MPaand a density of greater than 1.5 g/cc.
 2. The method of claim 1,further comprising: removing the substrate containing the stresseddiamond-like carbon film from the process chamber; positioning thesubstrate containing the stressed diamond-like carbon film in a thermalannealing chamber, wherein the stressed diamond-like carbon film isheated to produce the reduced-stress diamond-like carbon film during thethermal annealing process; and removing the substrate containing thereduced-stress diamond-like carbon film from the thermal annealingchamber.
 3. The method of claim 2, wherein the stressed diamond-likecarbon film is heated to produce the reduced-stress diamond-like carbonfilm at a temperature of about 300° C. to about 500° C. for about 2minutes to about 15 minutes during the thermal annealing process.
 4. Themethod of claim 2, wherein the thermal annealing chamber is maintainedat a pressure of about 10 mTorr to about 100 Torr during the thermalannealing process.
 5. The method of claim 2, wherein the stresseddiamond-like carbon film is heated to produce the reduced-stressdiamond-like carbon film under an environment comprising a gas duringthe thermal annealing process, wherein the gas comprises nitrogen (N₂),argon, helium, neon, or any combination thereof.
 6. The method of claim1, wherein the compressive stress of reduced-stress diamond-like carbonfilm is about 40% to about 90% less than the compressive stress of thestressed diamond-like carbon film.
 7. The method of claim 1, wherein thestressed diamond-like carbon film has a compressive stress of about −600MPa to about −1,000 MPa, and wherein the reduced-stress diamond-likecarbon film has a compressive stress of about −150 MPa to about −400MPa.
 8. The method of claim 1, wherein the reduced-stress diamond-likecarbon film has an elastic modulus of greater than 60 GPa to about 200GPa.
 9. The method of claim 1, wherein the reduced-stress diamond-likecarbon film has a density of about 1.55 g/cc to less than 2 g/cc. 10.The method of claim 1, wherein the processing volume is maintained at apressure of about 5 mTorr to about 100 mTorr and the substrate ismaintained at a temperature of about 0° C. to about 50° C. whengenerating the plasma and depositing the stressed diamond-like carbonfilm on the substrate.
 11. The method of claim 1, wherein thereduced-stress diamond-like carbon film comprises about 50 atomicpercent to about 90 atomic percent of sp³ hybridized carbon atoms. 12.The method of claim 1, wherein the hydrocarbon compound comprisesethyne, propene, methane, butene, 1,3-dimethyladamantane,bicyclo[2.2.1]hepta-2,5-diene, adamantine, norbornene, or anycombination thereof.
 13. The method of claim 1, wherein the depositiongas further comprises helium, argon, xenon, neon, hydrogen (H₂), or anycombination thereof.
 14. The method of claim 1, wherein generating theplasma at the substrate further comprises applying a second RF bias tothe electrostatic chuck, wherein the electrostatic chuck has a chuckingelectrode and an RF electrode separate from the chucking electrode, andwherein the first RF bias is applied to the RF electrode and the secondRF bias is applied to the chucking electrode.
 15. The method of claim 1,wherein generating the plasma at the substrate further comprisesapplying a second RF bias to the electrostatic chuck, wherein the firstRF bias is provided at a power of about 10 watts to about 3,000 watts ata frequency of about 350 KHz to about 100 MHz, and wherein the second RFbias is provided at a power of about 10 watts to about 3,000 watts at afrequency of about 350 KHz to about 100 MHz.
 16. A method of processinga substrate, comprising: flowing a deposition gas comprising ahydrocarbon compound into a processing volume of a plasma processchamber having a substrate positioned on an electrostatic chuck, whereinthe processing volume is maintained at a pressure of about 0.5 mTorr toabout 10 Torr; generating a plasma above the substrate in the processingvolume by applying a first RF bias to the electrostatic chuck to deposita stressed diamond-like carbon film on the substrate, wherein thestressed diamond-like carbon film comprises about 50 atomic percent toabout 90 atomic percent of sp³ hybridized carbon atoms and has acompressive stress of −500 MPa or greater and a density of greater than1.5 g/cc; transferring the substrate containing the stresseddiamond-like carbon film from the plasma process chamber to a thermalannealing chamber; and heating the stressed diamond-like carbon film toa temperature of about 200° C. to about 600° C. for about 15 seconds toabout 60 minutes to produce a reduced-stress diamond-like carbon filmduring a thermal annealing process, wherein the reduced-stressdiamond-like carbon film comprises about 50 atomic percent to about 90atomic percent of sp³ hybridized carbon atoms and has a compressivestress of about −20 MPa to less than −500 MPa and a density of greaterthan 1.5 g/cc.
 17. The method of claim 16, wherein the compressivestress of reduced-stress diamond-like carbon film is about 40% to about90% less than the compressive stress of the stressed diamond-like carbonfilm.
 18. The method of claim 16, wherein the stressed diamond-likecarbon film has a compressive stress of about −600 MPa to about −1,000MPa and a density of about 1.55 g/cc to less than 2 g/cc, and whereinthe reduced-stress diamond-like carbon film has a compressive stress ofabout −150 MPa to about −400 MPa and a density of about 1.55 g/cc toless than 2 g/cc.
 19. The method of claim 16, wherein the reduced-stressdiamond-like carbon film has an elastic modulus of greater than 60 GPato about 200 GPa.
 20. A method of processing a substrate, comprising:flowing a deposition gas comprising a hydrocarbon compound into aprocessing volume of a process chamber having a substrate positioned onan electrostatic chuck; generating a plasma above the substrate in theprocessing volume by applying a first RF bias to the electrostatic chuckto deposit a stressed diamond-like carbon film on the substrate, whereinthe stressed diamond-like carbon film has a compressive stress of −500MPa or greater; and heating the stressed diamond-like carbon film to atemperature of about 200° C. to about 600° C. for about 15 seconds toabout 60 minutes to produce a reduced-stress diamond-like carbon filmduring a thermal annealing process, wherein the reduced-stressdiamond-like carbon film has a compressive stress of less than −500 MPaand a density of greater than 1.5 g/cc to about 2.1 g/cc, wherein thecompressive stress of reduced-stress diamond-like carbon film is about40% to about 90% less than the compressive stress of the stresseddiamond-like carbon film; forming a patterned photoresist layer over thereduced-stress diamond-like carbon film; etching the reduced-stressdiamond-like carbon film in a pattern corresponding with the patternedphotoresist layer; and etching the pattern into the substrate.